Google sometimes returns throttling TransientErrors that target specific sender domains. For example:
421 4.7.28 Gmail has detected an unusual rate of mail originating from your SPF domain [example.com 35]. To protect our users from spam, mail sent from your domain has been temporarily rate limited…
and
421 4.7.28 Gmail has detected an unusual rate of mail originating from your DKIM domain [example.com 36]. To protect our users from spam, mail sent from your domain has been temporarily rate limited.
The Community shaping.toml includes a shaping automation rule for handing these errors:
[[provider."gmail".automation]]
regex = "Our system has detected an unusual rate"
trigger = {Threshold="2/hr"}
action = {SetConfig={name="max_message_rate", value="10/minute"}}
duration = "30m"
But as far as I can tell, the max_message_rate config gets set on the Source IP level, which is problematic for shared Source Pools: One tenant sending emails too fast and triggering this error affects the max_message_rate of the Source IP and all other tenants on the same Source / Pool.
Is there any way to limit set up the shaping automation to set some sort of rate limit for the tenant instead of the source?